Vehicle occupant restraint belt retractors have heretofore been provided with an inertia responsive pendulum or the like for pivoting a lock bar into engagement with a pair of toothed ratchet plates attached to the ends of a belt reel so that the length of a restraint belt extending from the reel is fixed to restrain an occupant upon a vehicle seat. The locking engagement between the lock bar and the ratchet plate teeth is effectively maintained for as long as an occupant restraining load is imposed on the belt even though the inertia stimulus is terminated.
It is known to use the aforedescribed seat belt retractor in a seat belt system of the type having one end of the belt connected to the vehicle door so that the belt will be automatically unwound to an unrestraining position when the door is opened and rewound to the restraining position when the door is closed. Copending patent application Ser. No. 116,836 filed Jan. 30, 1980 now U.S. Pat. No. 4,277,037 provides a manually actuated release lever which forcibly disengages the lock bar from engagement with the toothed ratchet plates to permit unwinding rotation of the belt on the reel so that the occupant can open the door and alight from the vehicle in those instances where the belt retractor is employed in a door mounted automatic belt system.
It is characteristic of the aforedescribed automatic belt system that many layers of belt are wound upon the retractor when the door is closed and the belt is in the restraining position. It has been observed that the imposition of an occupant restraint load upon the belt subsequent to locking of the reel by the inertia responsive pendulum causes the belt to tighten or spool down on the reel and thereby extend the effective length of the restraint belt. Accordingly, prior patents such as U.S. Pat. No.
4,120,466, issued Oct. 17, 1978 to Adomiet, disclose self-actuating belt clamping devices in which the belt is guided around a roller on the end of a lever so that imposition of an occupant restraint load on the belt pivots the lever to clamp the belt between a locking surface carried on the lever and a locking surface mounted on the fixed retractor housing.
The present invention provides a manually actuable mechanism for forcibly disengaging the belt clamping mechanism simultaneous with forceable disengagement of the lock bar from the belt reel so that the retractor is restored to the normal unlocked condition permitting belt winding and unwinding.